PUPIL INVOLVEMENT IN PATIENTS WITH DIABETES-ASSOCIATED OCULOMOTOR NERVE PALSY

Objective: To derive a reliable estimate of the frequency of pupil inv olvement in patients with diabetes-associated oculomotor nerve palsy. Patients and Methods: In this prospective study, standardized enrollme nt criteria were employed to identify 26 consecutive patients with dia betes-associated oculomotor nerve palsy who were evaluated in a referr al-based, outpatient neuro-ophthalmology practice. A pupil ruler accur ate to within 0.5 mm was used to measure pupil diameters using a stand ardized procedure. The degree of anisocoria, if present, was recorded at each office visit until the ophthalmoplegia had resolved. Descripti ve statistics were used to identify the frequency and characteristics of pupil involvement. Results: Internal ophthalmoplegia occurred in 10 (38%) of 26 patients. The size of the anisocoria was 1 mm or less in most patients. None of the patients had a fully dilated unreactive pup il. Conclusions: Pupil involvement in patients with diabetes-associate d oculomotor nerve palsy occurs more often than has been previously re cognized, although the degree of anisocoria in and 1 patient is usuall y only 1 mm or less. Some characteristics of the internal ophthalmople gia may help to distinguish diabetic ophthalmoplegia from injury of th e oculomotor nerve caused by aneurysmal compression.